Only look at reflogs for relevant branches, not for git-annex branches

This speeds it up quite a bit.. May still be too slow in large repos.

Annex/Branch.hs

@@ -210,7 +210,7 @@ getHistorical :: RefDate -> FilePath -> Annex String
 getHistorical date file =
 	-- This check avoids some ugly error messages when the reflog
 	-- is empty.
-	ifM (null <$> inRepo (Git.RefLog.get' [Param "-n1"] (Just fullname)))
+	ifM (null <$> inRepo (Git.RefLog.get' [Param (fromRef fullname), Param "-n1"]))
 		( error ("No reflog for " ++ fromRef fullname)
 		, getRef (Git.Ref.dateRef fullname date) file
 		)

Command/Unused.hs

@@ -219,7 +219,7 @@ withKeysReferencedInGit refspec a = do
 	shaHead <- maybe (return Nothing) (inRepo . Git.Ref.sha) current
 	rs <- relevantrefs (shaHead, current)
 		<$> inRepo (Git.Command.pipeReadStrict [Param "show-ref"])
-	usedrefs <- applyRefSpec refspec rs (inRepo Git.RefLog.getAll)
+	usedrefs <- applyRefSpec refspec rs (getreflog rs)
 	forM_ usedrefs $
 		withKeysReferencedInGitRef a
   where
@@ -242,6 +242,7 @@ withKeysReferencedInGit refspec a = do
 				Git.Ref.headRef
 				: nubRefs (filter ((/= x) . fst) refs)
 		_ -> nubRefs refs
+	getreflog rs = inRepo $ Git.RefLog.getMulti rs
 
 {- Runs an action on keys referenced in the given Git reference which
  - differ from those referenced in the work tree. -}

Git/RefLog.hs

@@ -14,18 +14,17 @@ import Git.Sha
 
 {- Gets the reflog for a given branch. -}
 get :: Branch -> Repo -> IO [Sha]
-get b = get' [] (Just b)
+get b = getMulti [b]
 
-{- Gets all reflogs for all branches. -}
-getAll :: Repo -> IO [Sha]
-getAll = get' [Param "--all"] Nothing
+{- Gets reflogs for multiple branches. -}
+getMulti :: [Branch] -> Repo -> IO [Sha]
+getMulti bs = get' (map (Param . fromRef) bs)
 
-get' :: [CommandParam] -> Maybe Branch -> Repo -> IO [Sha]
-get' ps b = mapMaybe extractSha . lines <$$> pipeReadStrict ps'
+get' :: [CommandParam] -> Repo -> IO [Sha]
+get' ps = mapMaybe extractSha . lines <$$> pipeReadStrict ps'
   where
 	ps' = catMaybes
 		[ Just $ Param "log"
 		, Just $ Param "-g"
 		, Just $ Param "--format=%H"
-		, Param . fromRef <$> b
 		] ++ ps